US6514384B1 - Method for increasing filler retention of cellulosic fiber sheets - Google Patents
Method for increasing filler retention of cellulosic fiber sheets Download PDFInfo
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- US6514384B1 US6514384B1 US09/272,865 US27286599A US6514384B1 US 6514384 B1 US6514384 B1 US 6514384B1 US 27286599 A US27286599 A US 27286599A US 6514384 B1 US6514384 B1 US 6514384B1
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- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H23/00—Processes or apparatus for adding material to the pulp or to the paper
- D21H23/76—Processes or apparatus for adding material to the pulp or to the paper characterised by choice of auxiliary compounds which are added separately from at least one other compound, e.g. to improve the incorporation of the latter or to obtain an enhanced combined effect
- D21H23/765—Addition of all compounds to the pulp
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H11/00—Pulp or paper, comprising cellulose or lignocellulose fibres of natural origin only
- D21H11/16—Pulp or paper, comprising cellulose or lignocellulose fibres of natural origin only modified by a particular after-treatment
- D21H11/20—Chemically or biochemically modified fibres
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
- D21H17/20—Macromolecular organic compounds
- D21H17/21—Macromolecular organic compounds of natural origin; Derivatives thereof
- D21H17/24—Polysaccharides
- D21H17/28—Starch
- D21H17/29—Starch cationic
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
- D21H17/20—Macromolecular organic compounds
- D21H17/33—Synthetic macromolecular compounds
- D21H17/34—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
- D21H17/37—Polymers of unsaturated acids or derivatives thereof, e.g. polyacrylates
- D21H17/375—Poly(meth)acrylamide
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
- D21H17/20—Macromolecular organic compounds
- D21H17/33—Synthetic macromolecular compounds
- D21H17/34—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
- D21H17/41—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups
- D21H17/44—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups cationic
- D21H17/45—Nitrogen-containing groups
- D21H17/455—Nitrogen-containing groups comprising tertiary amine or being at least partially quaternised
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
- D21H17/20—Macromolecular organic compounds
- D21H17/33—Synthetic macromolecular compounds
- D21H17/46—Synthetic macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
- D21H17/54—Synthetic macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds obtained by reactions forming in the main chain of the macromolecule a linkage containing nitrogen
- D21H17/55—Polyamides; Polyaminoamides; Polyester-amides
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
- D21H17/63—Inorganic compounds
- D21H17/67—Water-insoluble compounds, e.g. fillers, pigments
- D21H17/675—Oxides, hydroxides or carbonates
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
- D21H17/63—Inorganic compounds
- D21H17/67—Water-insoluble compounds, e.g. fillers, pigments
- D21H17/68—Water-insoluble compounds, e.g. fillers, pigments siliceous, e.g. clays
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
- D21H21/06—Paper forming aids
- D21H21/10—Retention agents or drainage improvers
Definitions
- the present invention relates to a method for increasing filler retention of cellulosic fiber sheets and, more particularly, to a method for increasing filler retention for cellulosic fiber sheets by incorporating cellulosic fibers having increased anionic sites into the sheet.
- Fillers are often incorporated into cellulosic fiber sheets to provide paper products having enhanced printability and improved optical properties.
- the improvement provided by filler is limited by the amount of filler that can be retained by the fiber sheet. Accordingly, there exist a need for methods for increasing fiber capacity for filler and for increasing the filler retention of fiber sheets.
- the present invention seeks to fulfill these needs and provides further related advantages.
- the present invention provides a method for increasing filler retention of cellulosic fiber sheets.
- cellulosic fibers with increased anionic sites are treated with either positively charged and/or amphoteric filler particles or a cationic retention aid and negatively charged and/or amphoteric filler particles to provide sheets having increased filler retention.
- cellulosic fiber sheets with retained filler particles are provided.
- fiber sheets with retained positively charged and/or amphoteric filler particles are provided and, in another embodiment, the fiber sheets with retained negatively charged and/or amphoteric filler particles are provided.
- a method for increasing drainage from a papermaking furnish is provided.
- cellulosic fibers having increased anionic sites are incorporated into the furnish.
- FIG. 1 is a graph illustrating the change in sizing as a function of added cationic starch for fibrous sheets formed in accordance with the present invention
- FIG. 2 is a graph illustrating change in sizing as a function of added sizing agent for fibrous sheets formed in accordance with the present invention
- FIG. 3 is a graph illustrating percent filler retained as a function of added cationic starch for fibrous sheets formed in accordance with the present invention
- FIG. 4 is a graph illustrating percent ash in sheet as a function of added cationic starch for fibrous sheets formed in accordance with the present invention
- FIG. 5 is a graph illustrating drain time as a function of percent ash in sheet for fibrous sheets formed in accordance with the present invention
- FIG. 6 is a graph illustrating specific extensional stiffness as a function of percent ash in sheet for fibrous sheets formed in accordance with the present invention.
- FIG. 7 is a graph illustrating sheet strength as a function of percent ash in sheet for fibrous sheets formed in accordance with the present invention.
- the present invention provides a method for increasing filler retention in cellulosic fiber sheets.
- the method provides a cellulosic fiber sheet having retained filler particles.
- the resulting furnish can be drained at an increased rate relative to comparable furnishes lacking cellulosic fibers having increased anionic sites.
- filler particle refers to positively charged filler particles, negatively charged filler particles, and amphoteric filler particles.
- Amphoteric particles can be either formally charged (i.e., positively or negatively charged) or lack formal charge.
- Filler particles useful in the present invention are retained to cellulosic fibers through electrostatic bonding and association. Filler particles are generally noncellulosic particle additives combined with cellulosic fibers in the papermaking process to provide paper products having improved properties compared to paper products containing solely cellulosic fibers.
- the method of the invention includes applying either (1) positively charged and/or amphoteric filler particles or (2) cationic retention aid and negatively charged and/or amphoteric filler particles to cellulosic fibers having an increased number of fixed anionic sites.
- cellulosic fibers having an increased number of fixed anionic sites and “cellulosic fibers having increased anionic sites” refer to cellulosic fibers that have been modified such that the number of available anionic sites in the fibers is increased relative to corresponding fibers that have not been so modified.
- cellulose is a polar molecule that can form hydrogen bonds with other polar molecules, such as other cellulose molecules, to form fibers.
- Wood pulp fibers contain cellulose and hemicelluloses. Hemicelluloses contain a small number of carboxyl groups, providing the fibers with an overall negative charge. Accordingly, cellulose has some natural tendency to retain certain other materials.
- the method of the present invention provides for increasing the number of sites on the fiber to which bonding can occur. Accordingly, the addition of fixed anionic sites (e.g., carboxyl groups) to cellulose fibers provides the fibers with additional sites or positions through which bonding to cationic species can occur.
- the number of carboxyl groups added to a fiber is not particularly critical and can be controlled to provide fibers having the desired capacity for and retention of certain materials.
- the greater the number of fixed anionic sites for a cellulosic fiber the greater the filler retention of fiber sheets incorporating these fibers.
- increasing the number of carboxyl groups for a cellulosic fiber will increase its capacity to bond to cationic materials and its ability to retain those materials.
- bond refers to the electrostatic attractive force between oppositely charged materials, such as the anionic sites of a cellulose fiber and a cationic retention aid or positively charged filler particle.
- charged refers to materials and particles having formal positive and negative charges as well as to materials lacking formal charge but that are capable of electrostatic bonding and association through dipolar interactions.
- Anionic sites can be introduced into a cellulosic fiber by, for example, chemically modifying the fiber to increase the fiber's carboxyl content.
- Suitable methods for increasing a fiber's carboxyl content include any method that results in carboxyl group incorporation.
- carboxyl group introduction into cellulosic pulp is without substantial crosslinking and without substantially reducing the degree of polymerization of the pulp.
- Suitable methods are known in the art and include carboxylating cellulosic fibers such as described in U.S. Pat. No. 5,667,637, issued to Jewell et al., relating to cellulose carboxyethylation; U.S. Pat. No.
- CMC carboxymethylated cellulose
- Carboxylated cellulose fibers prepared by TEMPO catalyzed oxidation of cellulose is another suitable method for increasing the number of cellulose carboxyl groups.
- the fiber having increased anionic sites is treated with a positively charged filler particle.
- fibers with increased anionic sites can be combined with positively charged filler particles in an aqueous slurry and then deposited onto a foraminous support to form a wet composite. Once deposited, drainage of the slurry's dispersion medium from the wet composite occurs and, on subsequent drying, a sheet composed of cellulosic fibers with retained positively charged filler particles is produced.
- a mixture comprising a cationic filler and an anionic retention aid can be prepared and then added to a mixture of cellulosic fibers and a cationic retention aid.
- a positively charged filler such as cationic calcium carbonate (PCC) can be mixed with anionic polyacrylamide (i.e., anionic retention aid) and then added to a mixture of cellulosic fibers and a cationic retention aid (e.g., cationic starch).
- PCC cationic calcium carbonate
- Positively charged filler particles useful in the present invention include calcium carbonate, such as chalk and precipitated calcium carbonate (PCC); and aluminum trihydrate. Precipitated calcium carbonate is a preferred positively charged filler particle.
- negatively charged filler particles cannot be directly combined with such fibers to provide fibers having retained negatively charged filler particles.
- negatively charged filler particles are bonded to cellulosic fibers having increased anionic sites through an intermediate cationic retention aid.
- the cationic retention aid serves to bond to the cellulosic fibers through its anionic sites to provide fibers effectively having a cationic surface.
- negatively charged filler particles are bonded to the fibers' cationic surface to provide cellulosic fibers with retained negatively charged filler particles.
- Cellulosic fiber sheets with retained negatively charged filler particles can be formed sequentially by first treating fibers having increased anionic sites with a cationic retention aid and then treating the resulting fibers with negatively charged filler particles.
- the cationic retention aid can be combined with the anionic cellulosic fibers in an aqueous slurry. To the resulting slurry are added negatively charged filler particles.
- the presence of excessive amounts of cationic retention aid can render both the filler and fiber cationic, thereby reducing filler retention.
- the slurry can then be then deposited on a foraminous support and the wet composite dried to provide a sheet composed of cellulosic fibers having retained negatively charged filler particles.
- a mixture of cationic retention aid and negatively charged filler particles can be added to fibers having increased anionic sites.
- Cationic retention aids useful in the present invention include resins such as polyamide epichlorohydrin (commercially available under the tradename KYMENE from Hercules, Inc., Wilmington, Del., e.g., KYMENE 557H), polyethyleneimine, and polyacrylamide (commercially available under the tradename PAREZ from American Cyanamid Co., Stanford, Conn., e.g., PAREZ 631 NC and PAREZ 750B; CYPRO 514 and ACCOSTRENGTH 711 from American Cyanamid Co., Wayne, N.J.); cationic urea formaldehyde and melamine formaldehyde resins; cationic starch (commercially available under the designation WESCAT EF cationic starch from Western Polymer Co., Moses Lake, Wash.); cationic dialdehyde starch-based resin (commercially available under the designation CALDAS from Japan Carlet; National Starch 78-0080; COBOND 1000 from National Starch and Chemical Corp., New York, N.
- Negatively charged filler particles useful in the present invention include ground limestone or marble (calcium carbonate, supplied in strongly anionic form due to polyanionic dispersants), clay (mildly anionic), titanium dioxide (supplied with anionic dispersant), silicas, sodium aluminosilicates, and calcinated clay.
- Preferred negatively charged filler particles include clay and ground limestone particles.
- Cellulosic fibers are the basic component of the product of the present invention.
- Suitable fibers include any cellulosic fiber that can be modified to increase the fibers' fixed anionic sites.
- Suitable fibers include cellulosic fibers that can be modified to include carboxyl groups.
- cellulosic fibers are derived primarily from wood pulp. Suitable wood pulp fibers for use with the invention can be obtained from well-known chemical processes such as the Kraft and sulfite processes, with or without subsequent bleaching. The pulp fibers may also be processed by thermomechanical, chemithermomechanical methods, or combinations thereof. The preferred pulp fiber is produced by chemical methods.
- Ground wood fibers, recycled or secondary wood pulp fibers, and bleached and unbleached wood pulp fibers can be used.
- the preferred starting material is prepared from long fiber coniferous wood species, such as southern pine, Douglas fir, spruce, and hemlock. Details of the production of wood pulp fibers are well-known to those skilled in the art. These fibers are commercially available from a number of companies, including Weyerhaeuser Company. For example, suitable cellulose fibers produced from southern pine that are usable with the present invention are available from Weyerhaeuser Company under the designations CF416, NF405, PL416, FR516, and NB416.
- Suitable cellulose fibers can be obtained from northern softwood bleached kraft including Grand Prairie softwood and Prince Albert NBK; Douglas fir bleached kraft including Kamloops kraft; hardwood bleached kraft and sulfite pulps; and softwood bleached sulfite pulps.
- Other preferred pulps include bleached hardwood chemical pulps commonly used in the manufacture of fine papers.
- the wood pulp fibers useful in the present invention can also be pretreated prior to use with the present invention.
- This pretreatment may include physical treatment, such as subjecting the fibers to steam, or chemical treatment.
- pretreating fibers include the application of fire retardants to the fibers, and surfactants or other liquids, such as water or solvents, which modify the surface chemistry of the fibers.
- Other pretreatments include incorporation of antimicrobials, pigments, and densification or softening agents. Fibers pretreated with other chemicals, such as thermoplastic and thermosetting resins also may be used. Combinations of pretreatments also may be employed.
- the present invention provides cellulosic fiber sheets with retained filler particles.
- the filler particles are positively charged.
- positively charged filler particles are bonded to the fibers through the fibers' anionic sites or through a combination of anionic and cationic retention aids.
- the filler particles are negatively charged.
- negatively charged filler particles are bonded to the fibers through a cationic retention aid that is bonded to the fibers through the fibers' anionic sites.
- amphoteric particles are bonded to the fibers having fixed anionic sites through cationic and/or anionic retention aids.
- the fixed anionic sites include carboxyl groups that have been incorporated into the cellulosic fiber.
- the fiber sheets include carboxylated fibers to which have been retained ground limestone and/or clay particles through cationic polyacrylamide as the retention aid.
- a method for increasing the drainage rate for a papermaking machine is provided.
- cellulosic fibers having increased anionic sites are incorporated into a conventional papermaking furnish.
- water drainage from the furnish deposited on the forming wire of a papermachine is greatly increased compared to a similar furnish lacking fibers having retained filler particles.
- the fibers having increased anionic sites retain filler particles in the sheet, thereby reducing the amount of filler in the papermaking machine whitewater.
- a papermachine having its production speed limited by drainage can increase its production by incorporating fibers having increased anionic sites in accordance with the method of the invention.
- a furnish including fibers having increased anionic sites allows for the incorporation of highly refined fibers with relatively low freeness to provide a sheet with increased sheet strength and that can be formed with an acceptable drainage/production rate.
- the increased carboxyl content of cellulosic fibers provides the fibers with a great number of fixed anionic sites and results in increased filler capacity and retention for the fiber sheet incorporating these fibers.
- sizing is increased by increasing the retention of cationic sizing emulsion particles further resulting in improved printability.
- wet end drainage from papermaking machines and machine speed can be increased by partial flocculation of the highly carboxylated fibers and fines with cationic wet end additives.
- Sheet strength can also be increased by enhancing the bonding of recycled furnishes with highly carboxylated fiber addition, by increasing cationic starch retention, or by increased retention of other cationic polymer dry and wet strength additives.
- the handsheets were prepared from a stock mixture containing 70 percent by weight hardwood (i.e., Prince Albert hardwood pulp refined to 500 CSF in a Valley beater) and 30 percent by weight softwood.
- the softwood was Grand Prairie softwood pulp refined to 300 CSF.
- handsheets were prepared from two types of softwood pulp: (1) softwood pulp as described above without further treatment and having about 3.5 milliequivalents (meq) carboxyl groups/100 g pulp (designated GP in the FIGURES) and (2) carboxyethylated softwood prepared from the above softwood and having about 23 meq carboxyl groups/100 g pulp (designated CW in the FIGURES), pulp containing cellulosic fibers having increased anionic sites.
- softwood pulp as described above without further treatment and having about 3.5 milliequivalents (meq) carboxyl groups/100 g pulp
- CW meq carboxyl groups/100 g pulp
- Fine paper handsheets were formed with the following additives applied in order to a fibrous slurry (0.5 percent consistency) while stirring at 750 rpm in a Britt Jar:
- cationic starch added at 0.5, 1, 2, or 4 percent by weight based on the weight of total solids, followed by 1 minute of stirring;
- ASA alkyl succinic anhydride
- the sizing of the comparative sheets was determined by the Hercules Sizing Test (HST), which measured the number of seconds that ink is held on the paper's surface before soaking in and wetting the sheet.
- HST Hercules Sizing Test
- the results for handsheets incorporating GP (3.5 meq carboxyl groups/100 g pulp) and CW (23 meq carboxyl groups/100 g pulp) having 0.5, 1, 2, and 4 percent by weight cationic starch based on the total weight of solids and either 25, 35, and 45 percent by weight filler (PCC) based on the total weight of solids is shown in FIG. 1 .
- HST increases with decreasing filler and generally decreases with increasing cationic starch.
- Handsheets prepared from CW softwood generally showed significantly increased sizing, greater than about 50 percent or more, compared to GP softwood containing sheets.
- Handsheet sizing as a function of sizing agent for CW- and GP-containing handsheets is illustrated in FIG. 2 .
- sizing generally increases with increasing sizing agent and handsheets prepared from CW softwood generally showed significantly increased sizing, greater than about 50 percent or more, compared to GP-containing sheets.
- filler retention generally decreases with increasing cationic starch and handsheets prepared from CW softwood generally showed significantly increased filler retention, greater than about 5 percent or more, compared to GP-containing sheets.
- the amount of retained filler in a handsheet can be determined by ashing the handsheet.
- FIG. 4 compares the percent ash in handsheet for CW- and GP-containing handsheets as a function of percent cationic starch for 25, 35, and 45 percent filler added. Referring to FIG. 4, ash content generally decreases with increasing cationic starch and handsheets prepared from CW softwood generally showed increased ash content compared to GP-containing sheets. These results are consistent with those noted above relating to filler retention.
- Drainage time during sheet formation in a sheet mold was determined for CW- and GP-containing handsheets.
- Handsheet drain time as a function of ash content in the sheet was determined and the results presented in FIG. 5 . As shown in FIG. 5, drain time generally decreases with increasing filler retained and handsheets containing CW softwood had significantly decreased drain times, about 5 percent, compared to the GP handsheets.
- the time required for drainage for sheets formed in accordance with the present invention is less than for comparable sheets that do not include such filler retained fibers.
- the strength of handsheets containing CW softwood with increased retained filler was comparable to GP-containing handsheets having a lower amount of retained filler.
- Specific Extensional Stiffness (measured in meters) as a function of percent cationic starch for CW- and GP-containing handsheets at 25, 35, and 45 percent added filler is shown in FIG. 6 .
- stiffness generally increases with increasing starch and decreasing retained filler.
- the stiffness of the CW-containing sheets was slightly less but comparable to the GP-containing sheets.
- the sheet strenth scott bond (measured in J/M 2 ) as a function of percent ash in the sheet is illustrated in FIG. 7 .
- strength generally reases with increasing ash content and increasing retained filler.
- the strength of handsheets containing CW softwood was greater than for GP-containing handsheets. The result indicates that improved filler distribution result in increased strength at a given ash content.
- cellulosic fiber sheets formed in accordance with the present invention exhibit advantageous properties including increased filler retention, decreased drainage times, and increased sizing compared to comparable sheets lacking fibers having increased anionic sites. Furthermore, the sheets of the invention do not suffer from a decrease in strength as a result of their increased filler retention.
- a 12 inch ⁇ 12 inch deckle box was used to form handsheets of approximately 26 g/m 2 basis weight and approximately 240 kg/r 3 density on the forming wire described above. Five sheets were formed for each pulp. The sheets were not wet pressed. Dewatering of the handsheets was accomplished by passing the sheets still on the forming wire over a vacuum slit. The sheets were dried on a steam-heated drum dryer and cured in an oven for one hour at 105° C. Wet burst strength of the sheets was measured on a Thwing Albert Model 1300-177 Wet Burst Tester manufactured by Thwing Albert Instrument Co., Philadelphia, Pa., 19154. Eight measurements were made for each pulp and the average calculated and taken as the wet burst strength.
- Pulp Sample 5C prepared as described in Example 4 was washed with 1% CaC1 2 solution followed by water to produce a highly carboxylated pulp with the cations substantially all calcium, and is designated Sample 5C1.
- Sample 5C1 was blended with Grande Prairie Softwood northern bleached kraft in a ratio of 10% Sample 5C1 and 90% northern bleached kraft. This blend was used in the evaluations described in above and was compared to a pulp consisting of 100% Grande Prairie Softwood.
- the pulp blend containing 10% highly carboxylated fibers showed a 17% decrease in drain time and slightly improved wet burst strength in comparison to the 100% Grande Prairie pulp at equal freeness. The results are summarized in Table 1.
- Example 4 the formation and drainage of a fiber furnish containing highly carboxylated fibers prepared as described in Example 4 is described increasing the amount of hypohalite used and/or by extending the reaction time.
- three samples were prepared according to the following procedures.
- a buffer solution was prepared using 10.1 g NaHCO 3 and 8.48 g Na 2 CO 3 dissolved in 2.6 L of deionized water. In this was dispersed 100 g dry basis of northern softwood kraft pulp followed by the addition of 1.4 kg ice. The pH was about 9.7.
- An oxidizing mixture was prepared by first mixing 200 mg TEMPO with 2.00 g NaBr then adding ⁇ 5 mnL of a total 40 mL 5.25% NaOCl solution and mixing well until the oily material was dissolved. This was added to the buffered pulp slurry. The remaining 35 mL of NaOCl solution was added slowly over the next 22 minutes. The slurry was then drained, washed, and redispersed in water with 2.13 g NaBH 4 to make a total weight of 1336 g. After two hours the pulp from the reducing treatment was again drained and washed. Total carboxyl content was measured as 11 meq/100 g.
- the oxidizing mixture was made up of 427 mg TEMPO, 2.1 g NaBR and a total of 390 mL 5.25% NaOCl solution.
- pH had dropped to 9.5 and 3 g Na 2 CO 3 was added.
- pH had dropped to 9.0.
- 250 g of ice and 4 g Na 2 CO 3 were added.
- an additional 4 g of Na 2 CO 3 was added.
- the slurry was drained and washed.
- the oxidized pulp was treated with NaBH 4 as in Sample 5B. Total carboxyl content was 97 meq/100 g.
- Water retention values are an important property of cellulose papermaking fibers. Higher values often indicate higher surface areas or relatively higher fiber saturation points. In general, higher water retention values will correlate with increased strength properties of sheeted products. Water retention as reported herein has been determined by TAPPIUM256. Briefly, a sample of known dry weight is slurried in water, centrifuged, and reweighed. Water retention values, carboxyl content, and D.P. for the three products of the present example are summarized in Table 2.
Priority Applications (13)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/272,865 US6514384B1 (en) | 1999-03-19 | 1999-03-19 | Method for increasing filler retention of cellulosic fiber sheets |
BR0009122-7A BR0009122A (pt) | 1999-03-19 | 2000-03-16 | Processos para preparar uma folha de fibracelulósica tendo partìculas de carga retidas, epara aumentar a drenagem de água de umsuprimento fibroso depositado na tela formadorade uma máquina de fabricação de papel, folha defibra celulósica tendo partìculas de cargaretidas, de carga positivamente carregadasretidas, e de carga negativamente carregadasretidas, e, suprimento para fabricação de papelcompreendendo fibras celulósicas tendo sìtiosaniÈnicos aumentados e partìculas de cargapositivamente carregadas, e partìculas de carganegativamente carregadas |
NZ513713A NZ513713A (en) | 1999-03-19 | 2000-03-16 | Method for increasing filler retention of cellulosic fiber sheets |
JP2000606834A JP2003507583A (ja) | 1999-03-19 | 2000-03-16 | セルロース系繊維シートの填料歩留まりを向上させる方法 |
PCT/US2000/007039 WO2000056978A1 (en) | 1999-03-19 | 2000-03-16 | Method for increasing filler retention of cellulosic fiber sheets |
AU41722/00A AU769257B2 (en) | 1999-03-19 | 2000-03-16 | Method for increasing filler retention of cellulosic fiber sheets |
DE10084292T DE10084292T1 (de) | 1999-03-19 | 2000-03-16 | Verfahren zur Erhöhung der Füllstoffretention von Cellulosefaserbahnen |
EP00921394A EP1165889A1 (en) | 1999-03-19 | 2000-03-16 | Method for increasing filler retention of cellulosic fiber sheets |
NO20014060A NO20014060D0 (no) | 1999-03-19 | 2001-08-21 | Fremgangsmate for a oke fyllstoffretensjonen av celluloseholdige fiberark |
FI20011689A FI20011689A (fi) | 1999-03-19 | 2001-08-22 | Menetelmä selluloosakuituarkkien täyteaineretention lisäämiseksi |
SE0103016A SE523746C2 (sv) | 1999-03-19 | 2001-09-12 | Förfarande för ökning av fyllmedelsretention hos cellulosafiberark |
US10/327,701 US20030136532A1 (en) | 1999-03-19 | 2002-12-20 | Method for increasing filler retention of cellulosic fiber sheets |
US10/655,193 US6824649B2 (en) | 1999-03-19 | 2003-09-04 | Method for increasing filler retention of cellulosic fiber sheets |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/272,865 US6514384B1 (en) | 1999-03-19 | 1999-03-19 | Method for increasing filler retention of cellulosic fiber sheets |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US10/327,701 Continuation US20030136532A1 (en) | 1999-03-19 | 2002-12-20 | Method for increasing filler retention of cellulosic fiber sheets |
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US6514384B1 true US6514384B1 (en) | 2003-02-04 |
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US10/327,701 Abandoned US20030136532A1 (en) | 1999-03-19 | 2002-12-20 | Method for increasing filler retention of cellulosic fiber sheets |
US10/655,193 Expired - Fee Related US6824649B2 (en) | 1999-03-19 | 2003-09-04 | Method for increasing filler retention of cellulosic fiber sheets |
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Application Number | Title | Priority Date | Filing Date |
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US10/327,701 Abandoned US20030136532A1 (en) | 1999-03-19 | 2002-12-20 | Method for increasing filler retention of cellulosic fiber sheets |
US10/655,193 Expired - Fee Related US6824649B2 (en) | 1999-03-19 | 2003-09-04 | Method for increasing filler retention of cellulosic fiber sheets |
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US (3) | US6514384B1 (no) |
EP (1) | EP1165889A1 (no) |
JP (1) | JP2003507583A (no) |
AU (1) | AU769257B2 (no) |
BR (1) | BR0009122A (no) |
DE (1) | DE10084292T1 (no) |
FI (1) | FI20011689A (no) |
NO (1) | NO20014060D0 (no) |
NZ (1) | NZ513713A (no) |
SE (1) | SE523746C2 (no) |
WO (1) | WO2000056978A1 (no) |
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US20030083491A1 (en) * | 2001-06-06 | 2003-05-01 | Komen Joseph Lincoln | Hypochlorite free method for preparation of stable carboxylated carbohydrate products |
US20050028956A1 (en) * | 2003-08-05 | 2005-02-10 | Weyerhaeuser Company | Method for making tissue product containing carboxylated cellulosic fibers |
US20050028955A1 (en) * | 2003-08-05 | 2005-02-10 | Weyerhaeuser Company | Tissue product containing carboxylated cellulosic fibers |
US20050252629A1 (en) * | 2002-04-09 | 2005-11-17 | Makhlouf Laleg | Swollen starch-latex compositions for use in papermaking |
US20100062934A1 (en) * | 1996-12-13 | 2010-03-11 | Migaku Suzuki | Highly absorbent composite and method of making the same |
US20110277947A1 (en) * | 2010-05-11 | 2011-11-17 | Fpinnovations | Cellulose nanofilaments and method to produce same |
WO2014158104A3 (en) * | 2013-03-29 | 2015-03-05 | Siam Kraft Industry Co., Ltd. | Sheets with organic filler |
US9718980B2 (en) | 2012-08-14 | 2017-08-01 | Goldeast Paper (Jiangsu) Co., Ltd | Coating composition and coated paper |
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US6524348B1 (en) | 1999-03-19 | 2003-02-25 | Weyerhaeuser Company | Method of making carboxylated cellulose fibers and products of the method |
CN100373003C (zh) * | 2003-03-13 | 2008-03-05 | 王子制纸株式会社 | 纸的制造方法 |
US7001483B2 (en) | 2003-08-05 | 2006-02-21 | Weyerhaeuser Company | Apparatus for making carboxylated pulp fibers |
US7879994B2 (en) | 2003-11-28 | 2011-02-01 | Eastman Chemical Company | Cellulose interpolymers and method of oxidation |
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Citations (19)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4610801A (en) * | 1982-09-24 | 1986-09-09 | Blue Circle Industries Plc | Compositions comprising mineral particles in suspension and method of treating aqueous systems therewith |
EP0373306A2 (en) | 1988-12-10 | 1990-06-20 | Laporte Industries Limited | Colloidal composition and its use in the production of paper and paperboard |
EP0499448A1 (en) | 1991-02-15 | 1992-08-19 | Ciba Specialty Chemicals Water Treatments Limited | Production of paper |
US5147507A (en) * | 1990-03-08 | 1992-09-15 | Pfizer Inc. | Cationic polymer-modified filler material, process for its prepartion and method of its use in papermaking |
WO1993001353A1 (en) | 1991-07-02 | 1993-01-21 | Eka Nobel Ab | A process for the production of paper |
US5201998A (en) | 1982-05-28 | 1993-04-13 | Ciba-Geigy Corporation | Process for sizing paper with anionic hydrophobic sizing agents and cationic retention aids |
US5244542A (en) * | 1987-01-23 | 1993-09-14 | Ecc International Limited | Aqueous suspensions of calcium-containing fillers |
WO1995007303A1 (en) | 1993-09-07 | 1995-03-16 | Nederlandse Organisatie Voor Toegepast-Natuurwetenschappelijk Onderzoek Tno | Method for oxidising carbohydrates |
US5514249A (en) | 1993-07-06 | 1996-05-07 | Allied Colloids Limited | Production of paper |
US5522967A (en) * | 1994-05-27 | 1996-06-04 | Kimberly-Clark Corporation | Sulfonated cellulose and method of preparation |
US5543014A (en) | 1994-03-14 | 1996-08-06 | E. I. Du Pont De Nemours And Company | Process for preparing water soluble polyaluminosilicates |
US5611890A (en) * | 1995-04-07 | 1997-03-18 | The Proctor & Gamble Company | Tissue paper containing a fine particulate filler |
US5667637A (en) | 1995-11-03 | 1997-09-16 | Weyerhaeuser Company | Paper and paper-like products including water insoluble fibrous carboxyalkyl cellulose |
US5755930A (en) * | 1994-02-04 | 1998-05-26 | Allied Colloids Limited | Production of filled paper and compositions for use in this |
US5755828A (en) | 1996-12-18 | 1998-05-26 | Weyerhaeuser Company | Method and composition for increasing the strength of compositions containing high-bulk fibers |
WO1998024974A1 (en) | 1996-12-04 | 1998-06-11 | Kimberly-Clark Worldwide, Inc. | Method for making wet strength paper |
US5827398A (en) * | 1996-02-13 | 1998-10-27 | Allied Colloids Limited | Production of filled paper |
US5935383A (en) | 1996-12-04 | 1999-08-10 | Kimberly-Clark Worldwide, Inc. | Method for improved wet strength paper |
US5958180A (en) * | 1997-09-23 | 1999-09-28 | International Paper Company | Method for increasing the strength of a paper or paperboard product |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3804656A (en) * | 1972-02-22 | 1974-04-16 | Engelhard Min & Chem | Pigment dispersions and use thereof |
FI72557C (fi) * | 1984-01-11 | 1992-01-08 | Kemira Oy | Pappersframstaellningsfoerfarande och aemneskomposition foer anvaendning daeri. |
US4892590A (en) * | 1988-06-03 | 1990-01-09 | Pfizer Inc. | Precipitated calcium carbonate-cationic starch binder as retention aid system for papermaking |
US5006574A (en) * | 1989-02-10 | 1991-04-09 | Engelhard Corporation | Cationcally dispersed slurries of calcined kaolin clay |
US5169441A (en) * | 1990-12-17 | 1992-12-08 | Hercules Incorporated | Cationic dispersion and process for cationizing finely divided particulate matter |
US5336311A (en) * | 1992-07-07 | 1994-08-09 | Nord Kaolin Company | Cationic pigments |
-
1999
- 1999-03-19 US US09/272,865 patent/US6514384B1/en not_active Expired - Fee Related
-
2000
- 2000-03-16 AU AU41722/00A patent/AU769257B2/en not_active Ceased
- 2000-03-16 DE DE10084292T patent/DE10084292T1/de not_active Withdrawn
- 2000-03-16 WO PCT/US2000/007039 patent/WO2000056978A1/en not_active Application Discontinuation
- 2000-03-16 NZ NZ513713A patent/NZ513713A/en unknown
- 2000-03-16 BR BR0009122-7A patent/BR0009122A/pt not_active IP Right Cessation
- 2000-03-16 EP EP00921394A patent/EP1165889A1/en not_active Withdrawn
- 2000-03-16 JP JP2000606834A patent/JP2003507583A/ja active Pending
-
2001
- 2001-08-21 NO NO20014060A patent/NO20014060D0/no not_active Application Discontinuation
- 2001-08-22 FI FI20011689A patent/FI20011689A/fi not_active IP Right Cessation
- 2001-09-12 SE SE0103016A patent/SE523746C2/sv not_active IP Right Cessation
-
2002
- 2002-12-20 US US10/327,701 patent/US20030136532A1/en not_active Abandoned
-
2003
- 2003-09-04 US US10/655,193 patent/US6824649B2/en not_active Expired - Fee Related
Patent Citations (19)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5201998A (en) | 1982-05-28 | 1993-04-13 | Ciba-Geigy Corporation | Process for sizing paper with anionic hydrophobic sizing agents and cationic retention aids |
US4610801A (en) * | 1982-09-24 | 1986-09-09 | Blue Circle Industries Plc | Compositions comprising mineral particles in suspension and method of treating aqueous systems therewith |
US5244542A (en) * | 1987-01-23 | 1993-09-14 | Ecc International Limited | Aqueous suspensions of calcium-containing fillers |
EP0373306A2 (en) | 1988-12-10 | 1990-06-20 | Laporte Industries Limited | Colloidal composition and its use in the production of paper and paperboard |
US5147507A (en) * | 1990-03-08 | 1992-09-15 | Pfizer Inc. | Cationic polymer-modified filler material, process for its prepartion and method of its use in papermaking |
EP0499448A1 (en) | 1991-02-15 | 1992-08-19 | Ciba Specialty Chemicals Water Treatments Limited | Production of paper |
WO1993001353A1 (en) | 1991-07-02 | 1993-01-21 | Eka Nobel Ab | A process for the production of paper |
US5514249A (en) | 1993-07-06 | 1996-05-07 | Allied Colloids Limited | Production of paper |
WO1995007303A1 (en) | 1993-09-07 | 1995-03-16 | Nederlandse Organisatie Voor Toegepast-Natuurwetenschappelijk Onderzoek Tno | Method for oxidising carbohydrates |
US5755930A (en) * | 1994-02-04 | 1998-05-26 | Allied Colloids Limited | Production of filled paper and compositions for use in this |
US5543014A (en) | 1994-03-14 | 1996-08-06 | E. I. Du Pont De Nemours And Company | Process for preparing water soluble polyaluminosilicates |
US5522967A (en) * | 1994-05-27 | 1996-06-04 | Kimberly-Clark Corporation | Sulfonated cellulose and method of preparation |
US5611890A (en) * | 1995-04-07 | 1997-03-18 | The Proctor & Gamble Company | Tissue paper containing a fine particulate filler |
US5667637A (en) | 1995-11-03 | 1997-09-16 | Weyerhaeuser Company | Paper and paper-like products including water insoluble fibrous carboxyalkyl cellulose |
US5827398A (en) * | 1996-02-13 | 1998-10-27 | Allied Colloids Limited | Production of filled paper |
WO1998024974A1 (en) | 1996-12-04 | 1998-06-11 | Kimberly-Clark Worldwide, Inc. | Method for making wet strength paper |
US5935383A (en) | 1996-12-04 | 1999-08-10 | Kimberly-Clark Worldwide, Inc. | Method for improved wet strength paper |
US5755828A (en) | 1996-12-18 | 1998-05-26 | Weyerhaeuser Company | Method and composition for increasing the strength of compositions containing high-bulk fibers |
US5958180A (en) * | 1997-09-23 | 1999-09-28 | International Paper Company | Method for increasing the strength of a paper or paperboard product |
Non-Patent Citations (11)
Cited By (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20100062934A1 (en) * | 1996-12-13 | 2010-03-11 | Migaku Suzuki | Highly absorbent composite and method of making the same |
US6919447B2 (en) * | 2001-06-06 | 2005-07-19 | Weyerhaeuser Company | Hypochlorite free method for preparation of stable carboxylated carbohydrate products |
US20030083491A1 (en) * | 2001-06-06 | 2003-05-01 | Komen Joseph Lincoln | Hypochlorite free method for preparation of stable carboxylated carbohydrate products |
US20050252629A1 (en) * | 2002-04-09 | 2005-11-17 | Makhlouf Laleg | Swollen starch-latex compositions for use in papermaking |
US7625962B2 (en) * | 2002-04-09 | 2009-12-01 | FI Fpinnovations | Swollen starch-latex compositions for use in papermaking |
US8354004B2 (en) | 2002-04-09 | 2013-01-15 | Fpinnovations | Unruptured, ionic, swollen starch for use in papermaking |
US20050028955A1 (en) * | 2003-08-05 | 2005-02-10 | Weyerhaeuser Company | Tissue product containing carboxylated cellulosic fibers |
US20050028956A1 (en) * | 2003-08-05 | 2005-02-10 | Weyerhaeuser Company | Method for making tissue product containing carboxylated cellulosic fibers |
US20110277947A1 (en) * | 2010-05-11 | 2011-11-17 | Fpinnovations | Cellulose nanofilaments and method to produce same |
EP2569468B1 (en) | 2010-05-11 | 2017-01-25 | FPInnovations | Cellulose nanofilaments and method to produce same |
US9856607B2 (en) * | 2010-05-11 | 2018-01-02 | Fpinnovations | Cellulose nanofilaments and method to produce same |
US9718980B2 (en) | 2012-08-14 | 2017-08-01 | Goldeast Paper (Jiangsu) Co., Ltd | Coating composition and coated paper |
WO2014158104A3 (en) * | 2013-03-29 | 2015-03-05 | Siam Kraft Industry Co., Ltd. | Sheets with organic filler |
Also Published As
Publication number | Publication date |
---|---|
US20040045688A1 (en) | 2004-03-11 |
FI20011689A (fi) | 2001-08-22 |
DE10084292T1 (de) | 2002-03-14 |
US20030136532A1 (en) | 2003-07-24 |
BR0009122A (pt) | 2001-12-18 |
WO2000056978A1 (en) | 2000-09-28 |
SE0103016D0 (sv) | 2001-09-12 |
NO20014060L (no) | 2001-08-21 |
US6824649B2 (en) | 2004-11-30 |
SE0103016L (sv) | 2001-10-31 |
EP1165889A1 (en) | 2002-01-02 |
AU769257B2 (en) | 2004-01-22 |
AU4172200A (en) | 2000-10-09 |
JP2003507583A (ja) | 2003-02-25 |
NZ513713A (en) | 2004-04-30 |
SE523746C2 (sv) | 2004-05-11 |
NO20014060D0 (no) | 2001-08-21 |
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